xfinity not honoring promotion

Two days ago I initiated a chat with XFinity to switch my internet plan to a cheaper one since XFinity was doubling the price (this after two price increases in the last year). The first XFinity agent I chatted with was named Sumit and they offered me 300mbps for $50/month. Before they could complete my switch the agent disconnected and I was reconnected with a second agent, Monika.

Monika initially would not acknowledge that Sumit had offered 300mbps for $50/month but after chatting for some time she acknowledged that XFinity had offered me this price and then she also disconnected when I said I wanted to switch my plan to 300mbps for $50/month.

After Monika I was connected to an agent named Chand who told me she is not able to change my plan to the 300mbps for $50/month that XFinity offered and scheduled a callback saying I would be connected with XFinity's "Special Loyalty Team" to complete my transaction.

When I received the callback I was not connected with XFinity's "Special Loyalty Team" and was instead connected with a regular agent who also would not honor XFinity's offer to me of 300mbps for $50/month and also tried to upsell me into a $90/month plan. When I told her that I expected XFinity to honor the offer they made of $50/month for 300mbps I was finally connected to the "Special Loyalty Team" agent I was supposed to have been connected with in the first place-Kristine.

And all Kristine did was try to upsell me into a $90/month plan as well-they admitted that XFinity had offered 300mbps for $50/month but said that they could not change my plan in their system so I asked to be connected with a supervisor. As their supervisor was unavailable they told me they'd have the supervisor email me about the plan. This was two days ago and I have not received my email.

After wasting three hours of my life getting the runaround from XFinity I am making this post to reach someone at XFinity who will keep their word and honor the deal the company made for 300mbps at $50/month.

Thanks in advance.